06-05-2014, 01:17 PM
WEB BASED MONITORING AND CONTROLING OF INDUSTRIAL PROCESSES
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INTRODUCTION
The World Wide Web has made it possible to send a lot of data from one side of the world to the other side in almost no time. The use of the Internet for real-time interaction of the remote controlling and monitoring of the plants would give us many can advantages. Two main problems should be faced before the web based control and monitoring can be implemented.
1.The aspect of time delay, which can lead to irregular data transmission and data loss.
2. The problem of security.
WHAT IS WEB BASED MONITORING AND CONTROL ?
The web based monitoring and control (WBMC) can be described as the whole of operations performed to control or monitor a system situated in a closed network. It enables commercial data to their customers and managers. Easily achieving the real time status of process plants , suitable for
implementing advance control. It allows controllers to directly talk to the internet .It can be used to monitor and control smart devices from the internet.
REQUIREMENT SPECIFICATIONS
Tasks, which require a deterministic timing regime should be avoided because they may not be achievable due to web-related traffic delay. I t is necessary to minimize the communication load between the Internet level and the existing control level .Information exchange between process plants and Internet-based clients can be achieved through corporate systems .Reliability and the possible system failures should be also considered in order to keep the system robustness from the system architecture point of view.
INFORMATION ARCHITECTURE
Resolution: Abstraction levels for data vary among all the levels in the architecture. The higher the level is, the more abstract the data is. Reliability: Just as communication response time must decrease as one descends through the levels of the information architecture, the required level of reliability increases.
Reparability: The reparability considers the ease with which control and computing devices can be maintained.
Open Secure Shell
What is SSH & Open SSH
Secure Shell (SSH) is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client (running SSH server and SSH client programs, respectively). The protocol specification distinguishes two major versions that are referred to as SSH-1 and SSH-2.OpenSSH (Open BSD Secure Shell) is a set of computer programs providing encrypted communication sessions over a computer network using the SSH protocol. It was created as an open source alternative to the proprietary Secure Shell software suite offered by SSH Communications Security.
The Need For SSH
With the evolution of the internet, services such as file transfers, remote logins, and remote command executions became possible. Existing implementations of protocols that supported these services included ftp, rcp, telnet, rlogin, and rsh. Problem existed with these protocols. They lacked security ! (r-commands)Possible for an intruder to intercept and read data.
Telnet was especially risky:
Plaintext user name and password was easily intercepted over the network.
A new protocol was needed to fix these security problems.
Why Open SSH?
The SSH protocol encrypts all traffic between machines are encrypted. Telnet does not encrypt any information, passwords and account ids are passed in the clear. Open SSH is a free program implementing the SSH protocol Open SSH has been reviewed by team of security expert to reduce the number of bugs in it